Microsoft registered a trademark with the United States Patent and Trademark Office on January 13, under both class 9 and class 41. Class 9 designates it as game software, while class 41 designates it as “online game software.”
It should be noted that Microsoft still holds another live trademark for Phantom Dust. This was filed in 2003, and may be associated with a shut down project.
This trademark (as reported by Dualshockers) indicates that the Phantom Dust Xbox One exclusive may still be in the works, contrary to the suspicions of many fans. The exclusive project was announced during E3 2014, but the studio working on it was shut down last year. There hasn’t been another developer assigned to the project, but Microsoft’s Phil Spencer has insisted that it’s “still committed” to the game.